Six-time Grand Slam champion Novak Djokovic was relieved to eventually see off the threat of Grigor Dimitrov after a "tough" Wimbledon semi-final.

The 2011 Wimbledon winner, who lost last year’s final to Andy Murray, beat the Scot’s conqueror 6-4 3-6 7-6 (7/2) 7-6 (9/7) to book a date with either Milos Raonic or seven-time All England Club champion Roger Federer.

He plays equally well when he's aggressive and when he's defending. He has improved immensely in the last six to eight months and you can see by his results.

Novak Djokovic

Top seed Djokovic was handed a thorough test by Dimitrov, who won the tournament's precursor at Queen’s Club before knocking out the reigning champion, but was relieved to overcome the challenge and reach his third Wimbledon final.

"It was his first semi-final, but he was fighting," the Serb said upon leaving Centre Court. "It was a tough match overall. The fourth set could have gone either way.

"I thought I started well, a set and a break and break points for a double break. Like the last match against [Marin] Cilic, I allowed my opponent to come back to the match. Overall I'm just really glad to reach another Wimbledon final."

Dimitrov lifted the Wimbledon boys' crown six years ago and Djokovic was quick to lavish praise on the Bulgarian, who has ruffled the feathers of the tennis elite this season.

Quality

"He has quality shots, especially running forehand, and he has a great touch," added Djokovic.

"He plays equally well when he's aggressive and when he's defending. He has improved immensely in the last six to eight months and you can see by his results. It's a good win for me definitely."

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Djokovic last lifted a Grand Slam trophy at the Australian Open in 2013 and the 27-year-old understands he will have to raise his game for Sunday’s showpiece event if he is going to end his 18-month baron spell.

"I have lost the last couple of grand slam finals and all these matches I could have won," he admitted.

"I'm looking forward to the challenge. Whoever I play in the final I have to be on top of my game.

"It's a big challenge, it's a big match. This is Wimbledon final, and it's the biggest event we have in our sport."